I thought people might be interested in this link, which contains the simple process (sending an email basically, although further details supporting your position can't hurt) which outlines how -- anyone --- can apply for a Crown Court sentence to be referred to the Attorney General's Office as being unduly lenient. I saw this on a facebook forum

In view of the lenient sentence AND the fact of the previous conviction, thie may have been already passed back to the AG.

The fact that it MIGHT have already been passed back should not inhibit another appeal to the AG. especially in the event that nobody else has requested a review.
Indeed if the AG receives a welter of such requests from people claiming to have been at the schpool when the offence(s) was(were) carried out that flurry may tip the balance towards it being returned to the Appeal Court for review.

I don't think he interfered with me, but now I know his MO I really don't know. Thousands of others are in the same position.

I guess I’m in a similar position. I was in the house where he was a junior housemaster between 1967 and 1970. Although that is before the date of the offences for which he is now in prison it’s not unreasonable to think his perverted behaviour started earlier.